Field of the Invention
The present invention relates to a heavy duty pneumatic tire that may exhibit better performance with respect to wet grip, traveling noise and fuel consumption.
Description of the Related Art
Japanese Unexamined Patent application Publication No. 2006-315579 discloses a heavy duty pneumatic tire including a tread portion with a plurality of tread blocks that are divided by circumferentially extending main grooves and a plurality of lateral grooves. To economize fuel consumption of the tire above, it may be effective to increase a land ratio of the tread portion so that the tread portion has high rigidity.
On the other hand, to improve wet performance of tires, it may be effective to increase a number of pitch elements on the tread portion so that the tread portion has a large number of lateral groove edge elements. Here, the pitch element refers to a repeated design unit for a tread pattern of the tread portion, and each includes circumferentially adjacent one block and one lateral groove. Furthermore, to improve wet performance of tires, it may be effective to increase a groove width of each lateral groove.
However, a tread portion having a high land ratio usually tends to have excessively low groove volume that may exhibit poor wet grip performance. Furthermore, a tread portion having a large number of pitch elements usually tends to have low rigidity thereof that may cause high fuel consumption. Furthermore, lateral grooves with wide widths on a tread portion of a tire tend to generate large air pumping noise during traveling